INTENSITY OF MAGNETIC AND DIAMAGNETIC FORCES. 727 



paragraph, the quantity of water in each solution and the corre- 

 sponding diamagnetic repulsion, we shall, for the sake of sim- 

 plicity, approximatively increase the total attraction of each of 

 these solutions by 0"1 grm. 



19. In a preliminary experiment, the magnetism of four of the 

 above substances had been already compared with the magnetism 

 of the iron. To control the accuracy of the method, 1 shall 

 give the results here, so as to allow of the comparison of the 

 more recent with the earlier results ; at the same time I shall 

 limit myself in the following table to the columns A, C and D. 



20. Still earlier, with a current of less intensity, I had com- 

 pared the magnetism of the hydrated peroxide of iron of the 



* The weights of the quantities of the peroxide obtained from the five solu- 

 tions mentioned in the above series amounted to 



grms. 

 1-731 

 3-162 

 3-204 

 4-036 

 0-036 

 I am indebted for these determinations, as also those detailed in the note to 

 paragraph 22, to the kindness of M. D. Brandis. 



